Method and apparatus for loading flash lamps



E. WHITE Aug. 21, 1956 METHOD AND APPARATUS FOR LOADING FLASH LAMPSFiled March 3l, 1955 INVENTOR.

' EH? W//E' B@ 94%- WMS/EY NIETHUD AND APPARATUS FOR LOADING FLASHLAlVIPS Earl White, Pulaski County, Ark., assignor to WestinghouseElectric CorporationI East Pittsburgh, Pa., a corporation ofPennsylvania Application March 31, 1955, Serial No. 498,266

8 Claims. (Cl. 226-19) This invention relates to a method and apparatusfor loading llash lamps and, more particularly, to a method andapparatus for loading photoiiash lamp enevlopes with foil of twodi'lerent sizes.

In so-called focal-plane cameras the total exposure time is greatlyincreased over the total exposure time for the usual shutter typecameras and photoash lamps for use with focal-plane cameras must providea flash of relatively long duration and uniform intensity. ln `order toachieve such a relatively long and uniform flash, two sizes of foil areutilized. A coarse foil i-s loaded in the upper and side portions of theenvelope and iiner foil is loaded near the bottom-center portions of theenvelope and about the igniting filament and primer of the lamp. Onfiring the lamp the fine foil ignites rst the generated light comes to apeak after a relatively short time. The coarse foil ignites after theline foil and the peak of licht intensity for the ignition of the coarsefoil occurs somewhat later than the light-intensity peak for the finefoil. These two peaks of light combine to provide the focal-planephotoilash lamp with a flash of long duration and relatively uniformintensity and in a No. 6 focal-plane photoflash lamp, for example, theminimum duration at half peak of light intensity is normally about 30milliseconds. In the usual No. photoiiash lamp, in contrast, the minimumduration at half-peak light intensity is normally about 13 milliseconds.In order to achieve consistent results regarding the long and uniformpeak, it has been found that the coarse and line foils must besubstantially separate with the liner foil surrounding the ignitingfilament and primer so that it will ignite first. This problem ofseparation of the foils of different sizes has, -in the past, presenteda manufacturing problem for while the coarse foil can readily be loadedby exi-sting foil-loading equipment, this equipment is not adapted toload the line foil into the same bulb, which in the past has been loadedby hand after the coarse foil has been machine loaded.

It is the general object of the invention to avoid and overcome theforegoing and other difliculties of and objections to prior artpractices by the provision of an apparatus for machine loading differentsizes of foil for a focal-plane type photoilash lamp.

lt is a further object of this invention to provide a method for loadingdifferent sizes of foil into a single envelope for a focal-plane typephotoflash lamp.

The aforesaid objects of the invention, and other objects which willbecome apparent as the description proceeds, are achieved by providingan apparatus and method whereby both coarse and tine foils are loaded byvacuumloading techniques wherein the line foil is first loaded and thecoarse foil is later loaded, the coarse-foil loading tube being bent acritical amount so that the fine foil can be correctly positioned withinthe envelope.

For a better understanding of the invention reference should be had tothe accompanying drawing wherein:

Fig. 1 is a sectional elevational View of a suction-type loading headshowing the fine foil loading operation;

g United States Patent C ice Fig. 2 is an elevational view of thephotoflash lamp envelope showing the fine foil after loading;

Fig. 3 is a sectional elevational View of the coanse-foil suction typeloading head with the nue-foil loaded bulb in position on the head;

Fig. 4 is a sectional elevational View of the coarse-foil loading headduring the first stage of the loading operation;

Fig. 5 is an enlarged view taken on the line VkV in Fig. 4;

Fig. 6 is a sectional elevational view of the coarse-foil suction typeloading head showing the coarse foil being loaded;

Fig. 7 is an elevational view, partly in section, of the foil loadedbulb;

Fig. 8 is an elevational View of the completed lamp.

Although the principles of the invention are broadly applicable to anytype of photoiash lamp or other type of container which encl-oses foilmaterial of more than one coarseness, the invention is particularlyapplicable for loading foil into a focal-plane photoflash lamp, andparticularly a No. 6 type, and hence it has been so illustrated and willbe so described.

With specic reference to the form of the invention illustrated in thedrawing, the numeral 10 indicates generally a No. 6 type photoflash bulb(having a volume of 25 cc.) in position on the line-foil suction typeloading head 12 and in the process of being loaded with fine foil 13.This fine foil i3 may be shredded aluminum in the form of' ribbonshaving a thickness or' about 0.00052 and a width of about 0.0007.However, .magnesium or other suitable material may be used. The head l2is provided with a loading or inlet tube "i4 which projects through theneck of the bulb and terminating within it. The other end of the loadingtube 14 is connected to the output of a foil shredding machine, such asillustrated in Patent Number 2,347,046 to W. J. Geiger, which shreddingmachine is set to produce fine foil. The interior portions of theloading tube 1.4 and connection conduit 16 should be smooth so as not toentrap any of the fine foil.

The head 12 is attached to the bed or frame 18 of the loading machineand the suction type head may have a generally cylindrical configurationclosed at one end with an annular seat portion 20 provided at the otheror bulb receiving end. This seat 1Z0 may be of rubber in order tosupport the envelope or bulb l0 in position on the head and seal it sothat a partial vacuum may be maintained within the bulb and within theloading head. A vacuum loading connection pipe 28 connects to theinterior of the load-ing head and is connected to a filter and pumpingmeans, as illustrated in the aforementioned Pate-nt Number 2,347,046 toGeiger.

The outer surface of that part `of the loading tube 14 which is adjacentthe neel; 23 of the bulb 10 when the bulb is in position on the loadinghead 12 is provided with a restricting means 24 which may take the formof a washer so that only a narrow gap 26 remains between the periphery:of the washer 24 and the bulb neel; 23. This Serves to contain theloaded fine foil E3 within the envelope.

The operation o-f the line foil loading head is essentially as describedin the aforementioned Geiger patent and briefly the suction means (notshown) causes fine foil to be sucked through the smooth conduit 16, nefoil loading tube 14 and into the envelope 10. The gas stream created bythe suction passes between the restriction 26 created by the washer 24and the bulb neck 23 and on through the suction means connection pipe28. Since the line foil cannot pass the restriction 26 it remains withinthe envelope; the gap of the restriction may be about 0.029", forexample, although this is not critical.

fter a suflicient quantity of the tine coil has been loaded into theenvelope, which in the case of a No. 6 type lamp may be 13 mg. of linefoil, the Suction producing means is shut off and the recurrent iiow ofgas into the envelope through the restriction 26 causes the ne foil tobe distributed throughout the envelope. The tine-foil loaded bulb maythen be removed from the loading head 12, as illustrated in Fig. 2.

The tine-foil loaded bulb is then placed upon a co-arsefoil suction head12a as illustrated in Fig. 3, and such a head substantially correspondsto the tine-foil suction head 12 shown in Fig. l except that the portionof the coarsefoil loading tube 14a which projects into the envelope 10is bent at an angle of at least 5 degrees and not more than lO degreeswith respect to the axis ot the envelope, with the optimum bend for thecoarse-foil loading tube 14a being S degrees with respect to the axis ofthe envelope.

The coarse-foil suction head 12a is connected to a second suctionproducing means through pipe 28a, such suction means being substantiallyas illustrated in the aforementioned Geiger patent. The loading tube 14ais connected through a smooth conduit 16a to a foil shredding machine asillustrated in the aforementioned Geiger patent, which machine is set toproduce coarse foil. When the suction producing means is turned on asillustrated in Fig. 4 the line foil 13 is sucked down until it isadjacent the restriction 26a between the washer 24a and the envelopeneck, see Figs. 4 and 5. If the amount of bend for the coarse-foilloading tube extremity which projects beyond the washer 2da into theenvelope 1li is less than 5 degrees with respect to the envelope axis ithas been found that the line toil will tend to catch on the end of theloading tube and also be displaced to the side and substantially all ofthe loaded fine foil will not be sucked down to a position which isadjacent the lamp neck as illustrated in Fig. 4. Also the coarse foilmay not be loaded directly on top of the iine foil, as is desired. Ifall of the line foil is not sucked down to this central position, someof the iine toil will be admixed with the coarse foil or positioned toone side or" the envelope after the loading is complete and the dashproduced by the lamp will be variable depending upon the amount of foiladmixture and the relative positioning or the iine and the coarse foils.lf the amount of bend of the extremity of the coarse foil loading tube14a which projects within the envelope is greater than l() degrees, somediiculty may be experienced in loading the lamp onto the coarse foilloading head.

After the fine foil has been sucked to a position adjacent the envelopeneck and restriction 26a as illustrated in Fig. 4, the coarse foilshredding machine is turned on and the coarse foil 29 is sucked into theenvelope to a position above the ne foil. ln the case of a No. 6 typefocal plane photoash lamp, it has been found that mg. of coarse foil aresatisfactory and after this amount of coarse foil has been loaded thecoarse-foil shredding machine is turned off and the suction producingmeans is also turned oil. In the case of a No. 6 lamp the shreddedaluminum coarse foil may have a thickness of about 0.0012 and a width ofabout 0.0018. When the suction producing means is turned ofi, therecurrent dow of gas into the envelope will cause the tine foil and thecoarse foil to snap into position as illustrated in Fig. 7 and, as thereshown, the two diterent sizes of foil are substantially separated fromone another with the smaller size toil in a centered position andclosest to the envelope neck.

The mount' 30 carrying the lead conductors 32, lam'ent 31a and primer 35are then sealed to the envelope ne'ck and an oxygen gas-ll inserted intothe envelope by techniques which are well-known. The base 36 is thencemented to the envelope neck and the lead lconductors 2 areelectrically conducted to the base to complete the fabrication of thelamp, a completely fabricated llamp 4 being illustrated in Fig. 8. Whenthe mount30 carrying thev iilament 34 is inserted into the envelope, thefilament will contact the centrally located tine foil so that the primer35 will be surrounded by the tine foil which will be hunched about theprimer and filament in a radius of about 3/8, in the case or a No. 6type lamp, for example.

As is well-known, the envelope llt) may be provided with both aninternal and an externalcoating of protective lacquer in order toprovide against violent envelope eruption against the thermal andmechanical shocks generated by the actinic reaction. In this case theinternal lacquer coating may be of a heat resistant acrylic resin, whichis applied before the foil is introduced into the lamp and the externallacquer coating may be of a high tensile strength cellulose acetate,which is applied after the lamp is `completely fabricated.Alternatively, the internal and external lacquer may be replaced by asingle coating of external lacquer such as cellulose-acetate butyrate,which is applied by dipping after the lamp is completely fabricated.Also, as is well-known, 'the inwardly extending extremities of thelead-in conductors 32 carry a small amount such as about 1 milligram ofprimer material 35 consisting of 90% zirconium and 10% potassiumperchlorate and the envelope encloses an oxygen gas-till at a pressureof about 600 mm. mercury, for example.

It will be recognized that the objects of the invention have beenachieved by providing a method and apparatus for machine loading foil ofdifferent sizes into the envelope of a photoash lamp which isparticularly adapted for use with focal-plane type cameras. Alsoprovided have been an allowable and an optimum degree of bend for thecoarse foil loading tube, which bend allows the coarse foil to bemachine loaded.

While in accordance with the patent statutes one best known embodimentof the invention has been illustrated and described in detail, it is tobe particularly understood that the invention is not limited thereto orthereby.

I claim:

1. The method of filling a photoiiash lamp envelope having an open neckcentered about the envelope axis with shredded foil of two diterentsizes so that the different sizes of foil are substantially separatedfrom one another with the smaller size foil closest to the envelopeneck, comprising placing said envelope over a tine-foil loading tube sothat said tube projects through said open neck into said envelope,carrying iine kfoil into said envelope through said tube by a stream ofgas leaving said envelope between said neck and said tube, removing saidenvelope from said tine foil loading tube, placing said tine-foil loadedenvelope over a coarse foil loading tube so that said coarse foilloading tube projects through said neck into said envelope, the portionof said coarsefoil loading tube which projects into said envelope beingbent at least 5 and not more than 10 with Arespect to the axis of saidenvelope, forcing said fine foil to a position adjacent said envelopeneck by a gas stream through said tube leaving said envelope betweensaid neck and said coarse-foil loading tube, carrying' coarse foil intosaid envelope through said -coarse-foil loading tube by a gas streamleaving said envelope between said neck and said tube, distributing saidshredded foil as uniformly as possible throughout said envelope by therecurrent liow of gas therein, and removing said 'envelope from saidcoarse foil loading tube.

2. The method of lling a photoflash lamp envelope with relatively coarseshredded foil which envelope has an open neck centered about theenvelope axis and a iilling of relatively fine shredded foil, so thatthe different sizes of foil are substantially separated from one anotherwith the iiner size foil closest to the envelope neck, comprisingplacing a coarse-foil loading tube through said neck into said envelope,the portion of said coarse-foil loading tube which projects into saidenvelope being bent at least 5 and not more than 10 with respect to theaxis of said envelope, forming said fine foil filling to a positionadjacent said envelope neck by means of a gas stream leaving saidenvelope between said neck and said coarse-foil loading tube, carryingcoarse foil into said envelope through said coarse-foil loading tube bymeans of a gas stream leaving said envelope between said neck and saidtube, distributing said shredded foil as uniformly as possiblethroughout said envelope by the recurrent ow of gas therein, andremoving said coarse-foil loading tube from said neck.

3. The method of lling a photoflash lamp envelope having an open neckcentered about the envelope axis with shredded foil of two differentsizes so that the different sizes of foil are substantially separatedfrom one another with the smaller size foil closest to the envelopeneck, comprising placing said envelope over a line-foil loading tube sothat said tube projects through said open neck into said envelope,carrying fine `foil into said envelope through said tube by a stream ofgas leaving said envelope between said neck and said tube, removing saidenvelope from said fine-foil loading tube, placing said line-foil loadedenvelope over a coarse foil loading tube so that said coarse foilloading tube projects through said neck into said envelope, the portionof said coarse-foil load* ing tube which projects into said envelopebeing bent about 8 with respect to the axis of said envelope, forcingsaid fine foil to a position adjacent said envelope neck by a gas streamthrough said tube leaving said envelope between said neck and saidcoarse-foil loading tube, carrying coarse foil into said envelopethrough said coarsefoil loading tube by a gas stream leaving saidenvelope between said neck and said tube, distributing said shreddedfoil as uniformly as possible throughout said envelope by the recurrentow of gas therein, and removing said envelope from said coarse foilloading tube.

4. An apparatus for filling a photollash envelope having an open neckcentered about the envelope axis with shredded foil of two differentsizes so that the different sizes of foil are substantially separatedfrom one another with the smaller foil closest to the envelope neck,said apparatus comprising a first suction head having an annular seatportion adapted to support and seal an envelope for Vacuum loading, asmooth feeding conduit connected to a tine-foil shredding machine andterminating in a tine-foil feeding tube adapted to project through saidenvelope neck within said envelope when in vacuum loading position, rstcontrollable vacuum producing means for producing a partial vacuumWithin said suction head to create a gas flow capable of carrying saidfine foil from said fine-foil shredding machine, through said feedconduit, said loading tube, into said envelope and between said envelopeneck and said loading tube into said suction head, restricting meansbetween said neck and said loading tube to substantially prevent saidtine foil being carried by said gas ow from said envelope into saidsuction head so that on cessation of gas ilow said ne foil will bedistributed within said envelope by the recurrent ow of gas therein, asecond suction head having an annular seat portion adapted to supportand seal said fine-foil loaded envelope for vacuum loading, a smoothfeeding conduit connecting to a coarse-foil shredding machine andterminating in a coarse-foil loading tube adapted to project throughsaid neck within said envelope when in loading position, the portion ofsaid coarse-foil loading tube which projects into said envelope beingbent at least and not more than 10 with respect to the envelope axis,second controllable vacuum producing means for producing a partialvacuum within said second suction head to create a gas ow capable ofcarrying coarse foil from said coarse-foil shredding machine, throughsaid coarse-foil feed conduit, said coarse-foil loading tube, into saidne-foil loaded envelope and between said envelope neck and saidcoarse-foil loading tube into said second suction head, second suctionhead restricting means between said neck and said coarse-foil loadingtube to substantially prevent said shedded foil being carried by saidgas flow from said envelope into said second suction head so that oncessation of said gas ow said loaded foil will be distributed Withinsaid envelope by the recurrent ow of gas therein.

5. An apparatus for filling a photoflash envelope with relatively coarsefoil, which envelope has an open neck centered about the envelope axisand a filling of relatively fine shredded foil, so that the differentsizes of foil are substantially separated from one another with thesmaller foil closest to the envelope neck, said apparatus comprising asuction head having an annular seat portion adapted to support and sealsaid tine-foil loaded envelope for vacuum loading, a smooth feedingconduit connecting to a coarse-foil shredding machine and terminating ina coarse-foil loading tube adapted to project through said neck withinsaid envelope when in loading position, the portion of said coarse-foilloading tube which projects into said envelope being bent at least 5 andnot more than 10 with respect to the envelope axis, controllable vacuumproducing means for producing a partial vacuum within said suction headto create a gas ow capable of carrying coarse foil from said coarse-foilshredding machine, through said coarse-foil feed conduit, saidcoarse-foil loading tube, into said tine-foil loaded envelope andbetween said envelope neck and said coarsefoil loading tube into saidsuction head, suction head restricting means between said neck and saidcoarse-foil loading tube to substantially prevent said shredded foilbeing carried by said gas ow from said envelope into said suction headso that on cessation of said gas ow the loaded foil will be distributedwithin said envelope by the recurrent ow of gas therein.

6. An apparatus for filling a photoash envelope having an open neckcentered about the envelope axis with shredded foil of two differentsizes so that the different sizes of foil are substantially separatedfrom one another with the smaller foil closest to the envelope neck,said apparatus comprising a first suction head having an annular seatportion adapted to support and seal an envelope for vacuum loading, asmooth feeding conduit connected to a tine-foil shredding machine andterminating in a ne-foil feeding tube adapted to project through saidenvelope neck within said envelope when in vacuum loading position, irstcontrollable vacuum producing means for producing a partial vacuumwithin said suction head to create a gas ow capable of carrying saidtine-foil from said ne-foil shredding machine, through said feedconduit, said loading tube, into said envelope and between said envelopeneck and said loading tube into said suction head, restricting meansbetween said neck and said loading tube to substantially prevent saidfine-foil being carried by said gas flow from said envelope into saidsuction head so that on cessation of said gas ow said ne-foil will bedistributed within said envelope by the recurrent flow of gas therein, asecond suction head having an annular seat portion adapted to supportand seal said fine-foil loaded envelope for vacuurn loading, a smoothfeeding conduit connecting to a coarse-foil shredding machine andterminating in a coarse-foil loading tube adapted to project throughsaid neck within said envelope when in loading position, the portion ofsaid coarse-foil loading tube which projects into said envelope beingbent about 8 with respect to the envelope axis, second controllablevacuum producing means for producing a partial vacuum within said secondsuction head to create a gas ow capable to carrying coarse foil fromsaid coarse-foil shredding machine, through said coarse-foil feedconduit, s aid coarsefoil loading tube, into said tine-soil loadedenvelope and between said envelope neck and said coarse-foil loadingtube into said second suction head, second suction head restrictingmeans between said neck and said coarse-foil loading tube tosubstantially prevent said shredded foil being carried by said gas owfrom said envelope into said second suction head so that on cessation ofsaid gas flow the loaded foil will be distributed within said envelopeby the recurrent'flow of gas therein.

7. The method of Alling a photoiiash lamp envelope having an open neckcentered about the envelope axis with shredded foil of two differentsizes so that the different sizes of foil are substantially separatedfrom one another with the smaller size foil closest to the envelopeneck, comprising placing said envelope over a fine-foil loading tube sothat said tube projects through said open neck into said envelope,carrying ne foil said envelope through said tube by a stream of gasleaving said envelope between said neck and said tube, removing saidenvelope from said ne foil loading tube, placing said ne-foil loadedenvelope over a coarse foil loading tube so that said coarse foilloading tube projects through said neck into said envelope, the portionof said coarsefoil loading tube which projects into said envelope bcingbent at least 5 with respect to the axis of said envelope and not morethan an amount which will allow said envelope to be placed over saidcoarse-foil loading tube, forcinc said tine foil to a position adjacentsaid envelope neck by a gas stream through said tube leaving saidenvelope between said neck and said coarse-foil loafing tube, carryingcoarse foil into said envelope through said coarse-foil loading tube bya. gas stream leaving said envelope between said neck and said tube,distributing said shredded foil as uniformly as possible throughout saidenvelope by the recurrent ow of gas therein, and removing saidenvelope-from said coarse foil loading tube.

8. An apparatus for lling a photoflash envelope having an open neckcentered about the envelope axis with shredded foil of two differentsizes so that the different sizes of foil are substantially separatedfrom one another with the smaller foil closest to the envelope neck,said apparatus comprising a iirst suction head having an annular seatportion adapted to support and seal an envelope for vacuum loading, asmooth feeding conduit connected to a tine-foil shredding machine andterminating in a line-foil feeding tube adapted to project through saidenvelope neck within said envelope when in vacuum loading position,first controllable vacuum producing means for producing a partial vacuumwithin said suction head to create a gas flow capable of carrying saidtine foil from said fine-foil shredding machine, through said feedconduit, said loading tube, into said envelope and between said envelopeneck and said loading tube into said suction head, restricting meansbetween said neck and said loading tube to substantially prevent saidfine foil being carried by said gas ilow from said envelope into saidsuction head so that on cessation of gas ow said tine foil will bedistributed within said envelope by the recurrent flow of gas therein, asecond suction head having an annular seat portion adapted to supportand seal said fine-foil loaded envelope for vacuurn loading, a smoothfeeding conduit connecting to a coarse-foil shredding machine andterminating in a coarse-foil loading tube adapted to project throughsaid neck within said envelope when in loading position, the portion ofsaid coarse-foil loading tube which projects into said envelope beingbent at least 5 with respect to the axis of said envelope and not morethan an amount which will allow said envelope to be loaded into saidsecond suction head, second controllable vacuum producing means forproducing a partial vacuum within said second suction head to create agas flow capable of carrying coarse foil from said coarse-foil shreddingmachine, through said coarsefoil feed conduit, said coarse-foil loadingtube, into said fine-foil loaded envelope and between said envelope neckand said coarsefoil loading tube into said second suction head, secondsuction head restricting means between said neck and said coarse-.foilloading tube to substantially prevent said shredded foil being carriedby said gas flow from said envelope into said second suction head sothat on cessation of said gas ow said loaded foil will be distributedwithin said envelope by the recurrent ow of gas therein.

No references cited,

